Microsoft Project files can get corrupted much the same as other application files. Project’s file format is MPP, and Project won’t open corrupted MPP files. An error message will usually pop up when users try to open corrupted MPP files.

However, that doesn’t necessarily mean there’s no way to salvage a corrupted Project file.

How can I fix Microsoft Project Files?

1. Use an alternative tool to open the files

Few users know that among the long list of supported file formats for Adobe Acrobat Reader, Microsoft Project-specific MPP files are also on the list.

That being said, if Microsoft Project cannot open the files for whatever reason, then opting for this familiar and yet efficient tool is the next best thing.

2. Is There a Previous Version Backup?

Users who have enabled File History and System Restore might be able to salvage previous versions of MPP files.

To do that, press the Windows key + E hotkey to open File Explorer.

Then open the folder that includes the MPP file.

Right-click the MPP file and select Properties.

Click the Previous Versions tab shown directly below.

Select a previous file version if there is one.

Then press the Restore button.

Open the previous MPP file version in Microsoft Project.

3. Fix the MPP With Recovery Toolbox for Project

Users who can’t restore MPP files will need to fix the corrupted files with file repair software such as Recovery Toolbox for Project.

To try out a trial version of the $27 Recovery Toolbox, click the Download button on that utility’s page.

Open the installer for Recovery Toolbox to add the software to Windows.

Open the Recovery Toolbox window shown directly below.

Click the folder icon button to select an MPP file to repair.

Press the Analyze button.

Click the Yes button to confirm.

The software will show users a preview of the recovered output.

Then select the Start recovery option to fix the file.

Click the Finish button.

4. Fix MPPs With Office Recovery

Alternatively, users can fix corrupted MPP files with the Office Recovery web app, which usually charges $9.99 for fixed files. Open the Repair MS Project File page in a browser.

Click Choose file to select a MPP file to repair.

Then press the Secure Upload and Repair button to fix the MPP.

Select the Get the repaired file option.

Users can then click a demo file title to download it.

To get a fully fixed file, select the Purchase full recovery for $9.99 option.

Thereafter, open the fixed MPP in Microsoft Project.

So, users might still be able to either recover previous MPP file versions or fix the corrupted files with third-party software. The Project Repair Kit is another third-party software utility for fixing MPP files that’s worth noting.

FAQ: Learn more about Microsoft Project

What is Microsoft Project?

Microsoft Project is one of the world’s most popular project management software, and it is part of the Microsoft Office suite.

Is Microsoft project free?

Unfortunately, Microsoft Project does not have any free features for its users.

Is Microsoft Project included in Office 365?

Yes, starting with Microsoft Project 2016 it became available for Office 365.

Editor’s Note:This post was originally published in September 2019 and has been since revamped and updated in May 2020 for freshness, accuracy, and comprehensiveness.